Irreversible Polymer Collapse in 2 and 3 Dimensions

We describe scaling arguments and simulations of the kinetics of the coil-to-globule transition. Scaling predicts and simulations confirm that irreversible collapse is dominated by diffusion of the polymer ends which accrete monomers and small aggregates. Exponents found by simulations agree closely with scaling relations. In three dimensions the collapse time is predicted to scale only linearly with polymer length. Our results are contrasted with de Gennes' mean-field theory of collapse in the reversible regime of small departure from θ-solvent conditions.